Field
Apparatuses and methods consistent with exemplary embodiments relate to a contents converting apparatus, a contents converting method, and a computer readable recording medium.
Description of the Related Art
With the development of electronic technologies, a method for consuming video contents is getting diverse. In the past, a user played video contents received from a broadcasting station or consumed video contents by connecting audiovisual (AV) devices like a video tape recorder (VTR), a digital versatile disc (DVD) player, and a Blu-ray disc (BD) player to a television (TV). Recently, a user may consume video contents using various devices such as a personal computer (PC), a smart phone, and a tablet PC. However, a lot of time and cost may be required to distribute high quality video contents through the Internet or a mobile network. Therefore, a demand has increased for a method for creating video contents from existing video contents distributing means, i.e., broadcasting, a VTR tape, a DVD, and a BD, all of which may be used in the devices such as the PC, the smart phone, and the tablet PC.
To generate contents of types that may be copied and may be consumed in the PC, the smart phone, the tablet PC, etc., when the DVD or the BD are the existing video contents distributing means and have contents recorded in a digital scheme, analog digital conversion (ADC) and AV compression are not required, and therefore the contents may be copied at low cost. However, a typical digital file copying method has a problem in that video contents may not be perfectly copied.
The typical digital file copying method copies all bits of information recognized as a file to make the same information as original information exist in a destination. Generally, an example of the typical digital file copying method may include a file copying method in a PC.
Even though contents look to a user as a title unit in the Blu-ray disc, stream files like a video, an audio, a sub-picture, a text-subtitle, a BD Java code, an image, etc., a navigation file instructing a method for playing a stream, and a file like metadata having a description regarding a disc, are present in an actual disc. That is, a title looks like a kind of data playing item to the user, and data that are used for actual playing become a portion or all of the stream files or a plurality of stream files. Therefore, the Blu-ray disc video contents correspond to compound digital contents, which are analyzed and played along with the stream files, like the video, the audio, the sub-picture, the text-subtitle, the BD Java code, and the image, and the navigation file. Therefore, a need exists for a contents converting method that converts content into a format that may be played in the PC, the smart phone, and the like, not merely a format that may be copied.
FIG. 1 is a diagram illustrating a relationship between a media file and a navigation information structure that are stored in a Blu-ray disc. The information structure is of video contents stored in the Blu-ray disc. Compound digital contents are stored in the Blu-ray disc, and a method for playing the same is determined by a movie object, a BD-J object, a Play List, a Play Item, and the like, which are navigation data.
FIG. 2 is a diagram illustrating a directory and a file structure of a Blu-ray disc. The directory is from a viewpoint of files. Here, a playing method means a file to be played, a playing scope within the file, a playing order of the playing scope, and the like. The BD-J object may include the playing method and applications, e.g., being displayed on a screen or controlling the Blu-ray player.
Therefore, there is a problem in that when the compound digital contents are copied only by the directory and a file name of FIG. 2 without understanding of the navigation data as illustrated in FIG. 1 (a file copying method), only a portion of an original title may be copied, or too much data may be copied. Therefore, a technology of understanding a navigation structure to export a title is needed.
FIG. 3 is a diagram illustrating a case in which one content consists of a plurality of files. In this case, Clip 1 and Clip 2 are stored as separate files, and therefore when only one of the Clip 1 and the Clip 2 is copied, it is impossible to perfectly play a video title. Further, even though the two files are copied, if Movie PlayList, which is a portion of the navigation data, is not understood and the files are copied by the existing method, it may not be understood what portion of any file needs to be played in what order, at a time of playing the files.
Further, to select and copy only some streams of one compound digital content that is stored in the Blu-ray disc, the streams may not be copied by the existing file copying method. A plurality of audio and graphic subtitles that are included in one video are contained in the Blu-ray disc contents while being multiplexed. However, some of the audio are not lines but may be an audio for describing a movie of a director, and some of the graphic subtitles may also be stored with graphics for a special use, which are not subtitles. Therefore some of the audio and some of the graphic subtitles may not be selectively copied even if not required. Therefore, in the case of the compound digital contents, a function of enabling a user to select and export only his/her desired contents is needed.
The plurality of compound digital contents (a plurality of titles) are generally present in the Blu-ray disc. However, a user may have trouble figuring out what title is present in the disc without playing a menu title, and therefore may have trouble determining what title needs to be exported without playing the Blu-ray disc. Therefore, separate information (for example, information needed to configure a menu helping the user to select his/her desired contents) helping the user to assort and export specific videos is needed.
In the case of converting and exporting contents, one stream for each kind is not exported, but there is a need to export a plurality of streams. However, to export the plurality of streams at a time, there is a need to change an existing decoder structure, and therefore there is a problem in that manufacturers need to correct a decoder chip on the whole. Therefore, an information structure and a method for exporting only one kind of stream or a plurality of streams in response to performance of a device need to be provided.
When converting the digital contents that are stored in the Blu-ray disc into a format that may be used in the devices such as the PC, the smart phone, the tablet PC, and the like, an International Organization for Standardization (ISO) base media file format (ISO BMFF) has been mainly used as a file format finally stored. The reason why the ISO BMFF format is mainly used is that the ISO BMFF has been supported by information technology (IT) devices over a long period of time, and as a result, there are many devices that may read the format. Further, MPEG-2 and MPEG-4 video decoders, MPEG4 Advanced Audio Coding (AAC) audio decoder, and the like are mainly supported in the PC, the smart phone, and the tablet, and the like, and therefore the contents having the ISO BMFF may be played in many devices. However, the compound digital contents that are stored in the Blu-ray disc may support the MPEG-2, the MPEG-4, and VC-1 in the case of the video, and therefore may be played in the IT devices without a big problem. However, the compound digital contents may support a high quality audio having AC-3, meridian lossless packing (MLP), and digital theater system (DTS) format in the case of the audio, such that the compound digital contents may not be played by the typical IT devices. Therefore, when converting and outputting the compound digital contents in the Blu-ray disc, a function of creating final results by adding contents that are not present in the original disc is needed. As such, it is possible to keep playing compatibility of converted results in more IT devices by a function of adding third contents.
Generally, the contents of the Blu-ray disc are protected by an advanced access content system (AACS). In the case of converting the contents protected by the AACS into other media and exporting and transmitting the converted contents, the contents are generally protected by a new contents protective system. Therefore, a process of releasing a code of the contents that are stored in the Blu-ray disc and coded, and encrypting the contents based on a new protective system scheme, is needed. In this case, an encryption key for new encryption is needed. A method for safely protecting the key is needed.